An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without a human pilot aboard. Small sized UAVs are increasingly used in various fields such as aerial photography, surveillance, scientific research, geological survey, and remote sensing. A camera may be equipped on the UAV through a platform system to implement a shooting task. In flight, real time images or video data captured by the camera can be real-time streamed back to a remote monitoring device on the ground through a wireless communication. A relative motion may be existed between the UAV and a target subject to be captured. To track the subject and obtain a clear and stabilized image, user may need to adjust an angle and a focus of the camera in real time through a remote controller based on the live images captured by the camera and displayed on the monitoring device.